This invention relates to wireless communications, and more particularly, to electronic devices with wireless communications capabilities.
Electronic devices such as cellular telephones, portable computers, media players, and hybrid devices are often provided with wireless communications capabilities. For example, cellular telephones may use long-range wireless communications to communicate with wireless base stations. Cellular telephones and other devices with wireless capabilities may communicate with the base stations using cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz. Wireless electronic devices may also use short-range wireless communications links. For example, wireless electronic devices may communicate with an access point using the Wi-Fi® (IEEE 802.11) bands at 2.4 GHz and 5.0 GHz and the Bluetooth® band at 2.4 GHz. Wireless electronic devices may also operate at the 3G data communications band (commonly referred to as UMTS or Universal Mobile Telecommunications Systems band) at 2170 MHz.
Wireless electronic devices include wireless communications circuitry. The wireless communications circuitry includes circuitry such as power amplifiers, low noise amplifiers, antennas, and transceiver circuitry. Power amplifiers are used to amplify radio-frequency signals generated by the transceiver circuitry. The radio-frequency signals are amplified by the power amplifiers prior to signal transmission to ensure that the signals are transmitted with sufficient signal strength.
Each radio-frequency band (e.g., 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz) is typically served by a respective power amplifier. Each of these power amplifiers generally has different performance specifications and therefore different heat-generation characteristics. For example, low-band amplifiers tend to generate less heat than high-band amplifiers when operated under similar conditions. Because operating settings and board placement can also impact thermal performance, proper optimization of a system with multiple radio-frequency power amplifiers can be challenging.
It would therefore be desirable to be able to provide wireless electronic devices with optimized power amplifier configurations.